Method of molding.



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PATENTED JULY 24, 1906.'.

No. 826,970. l

M. T. STEVENS. vMETHOD 0F MOLDING. APPLICATION FILED MAY l0. 1902.

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iiNiTEn srA'rE's PATENT oEEioED METHOD 0F MoLDlNG.

Specification of Letters Patent.

Patented July 24, 1906.

Application filed May l0, 1902i Serial No. 106,812.

To atl whom it may concern,.-

Beit known that I, MAURICE T. STEVENS, a citizen of the United States,residing at Harvey, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Methods of Molding, of which thefollowing is a s eciiication. This invention re ates to a method ofmolding and forming hollow building-blocks or artificial stone, pipes,and the like; and it consists in the several steps which will be morefully hereinafter described and claimed.

The present method contemplates the use of cement or other suitableplastic material for the formation of building-blocks, pipes, or otherdevices, which is rendered practicable by an assemblage of an innermoist filling of such material and end or surrounding layers or portionsof relatively dry material of a similar character to which pressure isapplied to produce a block, pipe, or other device wherein-the density isequal throughout the entire molded form. This desirable result isattained by the utilization of the relatively drylayers or portions atthe ends or surrounding the inner moist filling by having the said.relatively dry layers or portions absorb the moisture from the innerfilling to cause the cement or plastic material to closely adhere andbecome tenaciously homogeneous when dry and practically of the samedegree of hardness as the ordinary burned or fired building-blocks andpipe-sections now commonly in use.

Figure 1 is a perspective view of a mold Fig. 2 is a longitudinalvertical section vof the mold shown by Fig. 1. Fig. 3 is a transversevertical section taken through the plane of one' of the cores. Fig. 4 isa horizontal section of a portion of one end of the mold.

Similarnumerals of reference are employed to indicate correspondingparts in the several views.

The mold comprises suitable thin sheetmetal sides 1, a bottom 2, ends 3,removable end partitions 4, having terminal angular anges 5, and apressure-top 6,which is free to be moved or vibrated longitudinally fora purpose which will be presently explained. The one side 1 has a seriesof enlarged apertures 7 therethrough for the removable reception oftapering cores/ 8, which are of greater length than the width of theentire niold and are provided at their enlarged ends with gripping-pins9 for engagement by a Spanner or similar device to remove or apply thesaid cores. On each of the cores is a flanged sleeve 10, provided with aset-screw 11, whereby the cores will be held in proper projectedposition in relation to the mold as an entirety and by means of whichalso the width of the mold may be accommodated. The opposite end of eachof the cores has a squared or angular shank 12 embedded therein andformed with a projecting screwthreaded terminal 13, which engages ascrewthreaded opening 14 in the opposite side and a stationaryscrew-plate 15 over the said aperture 14. By the use of ends 3, varyingin length, molds having different widths can be produced, and the cores8 are constructed to accommodate this transverse adjustment. When thetransverse extent of the mold is varied or changed, the sleeves 10 arecorres ondingly shifted on the cores. so that the anges thereof willbear against the outer surface of'one of the sides 1, or that having theopening 7 therein. The ends 3 are held in place during the assemblage ofthe sides, bottom, and ends by suitable stop-strips 16 on the inneropposing faces or surfaces of the opposite sides 1, adjacent to the endsof the latter. The end partitions 4 are held inwardly a distance withinthe mold from the ends 3 by the ianges 5, and at a certain time the saidpartitions are withdrawn from the mold.

The top 6, as before indicated, is adapted to be vibrated longitudinallyand also to exert downward pressure on the plastic material or cementdisposed within the mold. The under side of the said top is corrugatedor otherwise shaped, as at 17, to cause an ornamental surface to beformed on the molded block` In applying pressure to the top 6 for thepurpose of rendering the material Within the mold homogeneous andequally dense many different methods can be employed; but the simplestmode of doing this would be to apply weights to the said top, andthereby force the latter closely down on the IOO material within themold, which is used in IIO strength and durability, and in the initialmethod of forming the same the removal-of the cores will facilitate thedrying out of the blocks, as air will be permitted to circulate throughthe openings. The tapered'form of the cores also assists in the removalof the same, as it will be understood that the gradually-reducingdiameter ofthe said'cores will be pulled through the gradually-enlargedportion ofthe openings in the-moldedblock.

The-essential-steps of the method consist, mainly, in-disposingl a layeror portion- 64- of relatively dry cement or other plastic material onthe bottoms of the mold. The cores 8 must necessarily be set upinv-operative re- Y lation to the casing; but itv is notactuallynecessary that the cores be inserted inthe mold before the lowerlayer or portion 64 of relatively dry cement or other plastic materialis disposed'insaid'mold. Again, if cores are not used in the mold thewhole interior of the moldl will'befree for the reception of the cementor plastic material. It will be understood', however, that the -coresmay be posi-Y tionedpreviousto the introduction of the cement or plasticmaterial in the mold, and it will be obviousA that so far as thepractical effect of the steps of' the method are concerned it isimmaterial Whether the cores be placed' in-position beforethe layers orportions of cement' or other plastic material are-introduced or not.After the lower layer or ortion 64 4of the cement is disposed in the mod a moist intermediatefilling 65 of similar cement or plastic material'is placed' on the lower relatively dry layeror portion 64 of suchmaterial and closely packedagainst the latter up to the openings for thecores in the mold'. The cores areV then inserted andv the parts of themold firmly secured, and the filling 65 is gradually introduced betweenVthe cores land packed over the latter, and finally a top layer' orportion 66 of' relatively dry cement or plastic material is disposedover the lling 65, and pressure is then applied to the wholel mass tocause the moisturefrom the illing65 to be absorbedl by the layers orportions 64 and 66 and facilitate the drying out of the i molded block,for example, and cause the lastic materialdas an entirety to closelyadliere and become tenaciously homogeneous when dry and practically of'the same degree of' hardness and density throughout the entire block.

As has been'set forth, the pressure can be applied to the top of themold or both to the top and bottom extremities, and' after the mass ofcement or plastic material has been thoroughly'pressed the forms of themold'sl having the cores therein will be relieved of said cores when theblocks have beceme suficiently dry, or at times said cores may be Thegeneral method has been explained,

wherein the salient features are-present;v but in addition to the stepspursued in forming the blocks the lend partitions4are-used and producecompartments atI the oppositeends of the mold', which are alsolilledwithquan tities or end layers 67' of1| relatively cement or other plasticmateriali of ay nature similar to that usedf in the formationof theblock. After the 'mold isfilled withv the plastic material in its twoconditions these partitions 4 are Withdrawn andtherel'a-tively drylayers y6'7 at the-end become united and press against the upper-and.zlowerrela-tively dry layers andthe intermediate` filling andalso-facilitate the absorption of the= excess of moisture'in! the saidfilling When thepressure is applied to--the meld in the diiferentwaysset forth.

The improved method herein d-isclosedf is economical and abuilding-block of= practical form can-be readil produced.

Havin 'thusful y described: the invention, what isc aimed as-newis I Theherein-d`escribed method? of molding, which consists in disposing alayerof' relatively dry plastic material in thebottomy ef'a mold,superimposing thereon a body mass of Sol IOO

moist plastic material', superi'mposing there'- on a second layer of'relativelygcry plastic material, forming'at each-end'of s lid mass awall of relatively dryv plastic material* in a separated' statetherefrom bringing said Wall?,

into contact with the-bodyv mass4 and layers,

applying pressure to theentire n'lasstoihomo geneously bind the .partsthereof; and then permitting the mass' to ha-rden:

IIO

vIn testimonywhereof I aliix my signature 1n presence of two Witnesses.-

MAURICE' T'. STEVENS. Witnesses:

P. H. CALLY, C. W. STEVENS.

